Title:
Experimental and numerical investigation of laminar flame speeds of H₂/CO/CO₂/N₂ mixtures

Simple item page
dc.contributor.advisor Seitzman, Jerry M.
dc.contributor.author Natarajan, Jayaprakash en_US
dc.contributor.committeeMember Jagoda, Jechiel I.
dc.contributor.committeeMember Martin, Scott
dc.contributor.committeeMember Menon, Suresh
dc.contributor.committeeMember Lieuwen, Timothy C.
dc.contributor.department Aerospace Engineering en_US
dc.date.accessioned 2008-06-10T20:45:43Z
dc.date.available 2008-06-10T20:45:43Z
dc.date.issued 2008-03-12 en_US
dc.description.abstract Coal derived synthetic gas (syngas) fuel is a promising solution for today s increasing demand for clean and reliable power. Syngas fuels are primarily mixtures of H2 and CO, often with large amounts of diluents such as N2, CO2, and H2O. The specific composition depends upon the fuel source and gasification technique. This requires gas turbine designers to develop fuel flexible combustors capable of operating with high conversion efficiency while maintaining low emissions for a wide range of syngas fuel mixtures. Design tools often used in combustor development require data on various fundamental gas combustion properties. For example, laminar flame speed is often an input as it has a significant impact upon the size and static stability of the combustor. Moreover it serves as a good validation parameter for leading kinetic models used for detailed combustion simulations. Thus the primary objective of this thesis is measurement of laminar flame speeds of syngas fuel mixtures at conditions relevant to ground-power gas turbines. To accomplish this goal, two flame speed measurement approaches were developed: a Bunsen flame approach modified to use the reaction zone area in order to reduce the influence of flame curvature on the measured flame speed and a stagnation flame approach employing a rounded bluff body. The modified Bunsen flame approach was validated against stretch-corrected approaches over a range of fuels and test conditions; the agreement is very good (less than 10% difference). Using the two measurement approaches, extensive flame speed information were obtained for lean syngas mixtures at a range of conditions: 1) 5 to 100% H2 in the H2/CO fuel mixture; 2) 300-700 K preheat temperature; 3) 1 to 15 atm pressure, and 4) 0-70% dilution with CO2 or N2. The second objective of this thesis is to use the flame speed data to validate leading kinetic mechanisms for syngas combustion. Comparisons of the experimental flame speeds to those predicted using detailed numerical simulations of strained and unstrained laminar flames indicate that all the current kinetic mechanisms tend to over predict the increase in flame speed with preheat temperature for medium and high H2 content fuel mixtures. A sensitivity analysis that includes reported uncertainties in rate constants reveals that the errors in the rate constants of the reactions involving HO2 seem to be the most likely cause for the observed higher preheat temperature dependence of the flame speeds. To enhance the accuracy of the current models, a more detailed sensitivity analysis based on temperature dependent reaction rate parameters should be considered as the problem seems to be in the intermediate temperature range (~800-1200 K). en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/22685
dc.publisher Georgia Institute of Technology en_US
dc.subject CO₂ dilution en_US
dc.subject Preheat en_US
dc.subject High pressure en_US
dc.subject Laminar flame speed en_US
dc.subject Syngas en_US
dc.subject N₂ dilution en_US
dc.subject.lcsh Gasoline, Synthetic
dc.subject.lcsh Combustion chambers
dc.subject.lcsh Flame
dc.subject.lcsh Gas-turbines
dc.title Experimental and numerical investigation of laminar flame speeds of H₂/CO/CO₂/N₂ mixtures en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Seitzman, Jerry M.
local.contributor.corporatename College of Engineering
local.contributor.corporatename Daniel Guggenheim School of Aerospace Engineering
local.relation.ispartofseries Doctor of Philosophy with a Major in Aerospace Engineering
relation.isAdvisorOfPublication a312077b-cd16-4664-ad12-3a719b7f798a
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
relation.isOrgUnitOfPublication a348b767-ea7e-4789-af1f-1f1d5925fb65
relation.isSeriesOfPublication f6a932db-1cde-43b5-bcab-bf573da55ed6
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Natarajan_Jayaprakash_200805_phd.pdf
Size:
1.39 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Theses and Dissertations